TUESDAY, Nov. 20 (HealthDay News) -- Men who had low muscle strength during their teen years are at increased risk for early death from several major causes, a new study contends.

The researchers from the Karolinska Institute in Sweden found that, for men, the effect of having low muscle strength in youth was similar to the well-known risk factors for early death such as being overweight or having high blood pressure.

The findings point to the need for young people, particularly those with very low strength, to get regular exercise to improve their muscular fitness, the study authors said in the report, published in the Nov. 20 online edition of the BMJ.

The study included more than 1 million Swedish males aged 16 to 19 who were followed for 24 years. The participants underwent strength tests at the start of the study. Early death was defined as death before age 55.

During the follow-up, 2.3 percent (more than 26,000) of the men died. The most common cause of death was suicide (22 percent), while cancer accounted for nearly 15 percent of deaths and cardiovascular diseases caused just less than 8 percent of deaths, the investigators found.

Adults who had high muscular strength as teens had a 20 percent to 35 percent lower risk of early death from any cause and also from cardiovascular diseases, independently of blood pressure or body-mass index (a measurement of fat based on height and weight), the results indicated.

In addition, those who were the strongest as teens also had a 20 percent to 30 percent lower risk of early death from suicide and were 65 percent less likely to be diagnosed with a mental health disorder, such as schizophrenia or mood disorders.

When the researchers looked at death rates from any cause, the rates ranged from 122.3 per 100,000 person years for those with the lowest muscle strength and 86.9 per 100,000 person years for those with the greatest muscle strength. Death rates for cardiovascular diseases were 9.5 and 5.6 per 100,000 person years, respectively, and for suicide were 24.6 and 16.9 per 100,000 person years, respectively.

The findings suggest that lower muscle strength in teens "is an emerging risk factor for major causes of death in young adulthood, such as suicide and cardiovascular diseases," study author Finn Rasmussen and colleagues concluded in a journal news release.

The results also point to the importance of exercise for children and teens, the authors noted.

The study found an association between low muscle strength during teen years and early death in men; it did not prove cause-and-effect.